This invention relates to an apparatus for the lifting of coils, spools, and the like having a carrying bolt which can be disposed into an inner opening and several clamping segments vertically movable at their outer circumference and thus radially expandable in an outward direction.
Such coils are wound onto the spools of winding machines, then tied and removed from the spool and transported to the site of their further processing. These coils which even in smaller versions often weigh over 100 kg have to be lifted. Here, as well as during the transport thereof, the coils have to be handled as carefully as possible in order not to cause the unwinding during the subsequent processing. It is particularly difficult to transport coils with a comparatively small diameter of the interior opening, since known apparatus is generally too large to be received into such small interior openings of the coils. Known lifting apparatus further more have a complicated construction and are expensive to manufacture, primarily due to the fact that they often serve other purposes in the handling of such coils.
Therefore, there is a need for an apparatus of the initially described type which has a simple construction, is effective when used and which is, above all, suitable for the handling of coils with smaller dimensions of the interior opening. The apparatus according to the invention meets these requirements and has a radially extending concentric guide track at the circumference of a carrying bolt for each clamping segment engaging a longitudinal guide slot of the clamping segment and having at least one tangentially extending crossbolt extending into an oblong aperture in the clamping segment. The crossbolt is arranged transversely to the longitudinal axis with the carrying bolt having an outer cone as a sliding guide for an inner cone of the clamping segments and with the clamping segments having a locking device for the carrying bolt operating in its radial withdrawn and upper position.
Such an apparatus consists of three units, that is, a carrying bolt, a clamping segment mounted thereon, and a locking device. It is therefore simple and inexpensive to manufacture as well as reliable when operated and can, since the clamping segments are mounted immediately around the central carrying bolt, be made with an extremely small external diameter of the clamping segments. It is therefore especially suited for the handling of coils with small diameters of the interior opening.
Additionally, the invention provides for the apparatus to have a bell-shaped top which overlaps the head of the clamping segments from above into which a guiding track engages and which has an inner cone as a sliding guide for an upper outer cone. The bell-shaped top serves as an additional upper guide of the clamping segments during their inward expansion movement so that these are not only guided by their oblong apertures but supported by the bell-shaped top as well.
The external diameter of the bell-shaped top can be larger than the maximum diameter of the clamping segments since, when the apparatus is disposed into the coil to be lifted, only the clamping segments engage in the interior opening of the coil. In this position, the locking device for the clamping segments can be released with respect to the carrying bolt so that the clamping segments drop and are expanded outwardly. During the subsequent lifting of the carrying bolt, the clamping segments firmly engage the inside of the coil opening with the weight of the coil increasing the friction between the clamping segments and the coils in an already-known manner.
According to another characteristic of the invention, a particularly effective locking device consists of concentric pins arranged at the head of each clamping segment and penetrating an opening in the bell-shaped top as well as of a releasable locking bar at the outside of the bell-shaped top engaging into a notch of the pin. If the apparatus has been inserted into the coil, the locking is released and the pins released so that the clamping segments can move into their lowering position.
According to an additional characteristic of the invention, a rotation hood is arranged above the cover plate of the bell-shaped top, rotatably but axially stable on the carrying bolt and having a joint locking bar for the pins of all of the clamping segments. When operating this joint locking bar, all clamping segments are simultaneously locked or released.
It is within the framework of the invention that the head of the clamping segments transcends their outer frictional surfaces radially in an outward direction. This has the advantage that the apparatus can be disposed into this until the clamping segment heads have been mounted on the coil, whereafter the locking for the clamping segments is released. In this simple fashion, the clamping segments form a stop, limiting the movement of the device into the coil.
In an alternate embodiment, the invention provides for a parallel construction with two crossbolts and corresponding oblong apertures between each clamping segment and the corresponding guide track. In this embodiment, the clamping segments are guided in a two fold fashion resulting in an exact guidance of the clamping segments.
Other features which are considered characteristic of the invention are set forth in the appended claims.
Although the invention is illustrated and described in relationship to specific embodiments, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.